Re: Novice question on A \ b

[Przemek Klosowski]

   octave:18> A = [ [1, 1, 2, 3]' [0, 0, 4, 4]']; b = [3, 0, -1, 0]'; A \ b
   ans =
       1.40000
      -1.00000

   I think this is the minimum norm solution, but Octave did not issue
   a warning.  What is wrong with my thinking?

You didn't say what value of 'b' you used; I tried 
b=[1.4 1.4 -1.2 .2]' and got the same result as you.
For what it is worth, so did the other leading brand.

The documentation on Arithmetic Operators says about the left division:

     If the system is not square, or if the coefficient matrix is
     singular, a minimum norm solution is computed.

so no warning is indicated. Where did you see the warning mentioned?



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